The present invention relates to a device for providing a moisture impervient barrier and a method for making the same.
Many ponds, lagoons and basement structures require a waterproof barrier on the floor and sides thereof. Examples of such applications are waste lagoons, cooling ponds for nuclear plants, and other situations where moisture impervient barriers are necessary at the bottom of a pond or lagoon. Also such barriers are desirable on the floor and walls of some basement structures.
One material which has been found useful for providing such waterproof barriers is bentonite. Bentonite is a clay material which is found in nature and which has the characteristic which enables it to expand upon being exposed to water. When the bentonite expands, it is capable of forming a waterproof barrier. Bentonite is a natural material which is mined and which has the property of being capable of absorbing a great deal of water so as to swell in response to this absorption.
One desirable way to use this bentonite material is to package it in sheets or rolls which can be placed on the bottom of the pond or lagoon so as to form a waterproof barrier thereon. One prior method for providing such a packaged bentonite sheet material utilized the following process:
(a) Using a base polyester sheet material having the ability to permit gases to escape therethrough in a laterial direction. PA0 (b) Applying an adhesive to the upper surface of this sheet material, the adhesive being formed from a starch-like glue. PA0 (c) Applying approximately one-fourth inch of bentonite on top of the adhesive. PA0 (d) Spraying a second coat of adhesive over the top of the bentonite. PA0 (e) Placing a scrim or fine mesh material on top of the adhesive. PA0 (f) Press rolling the above combination into an elongated flat sheet material. PA0 (g) Baking the sheet material in a long oven at approximately 300.degree. F. so as to bake all the moisture out of the sheet material and the bentonite. PA0 (a) Using a flat polyester sheet material, preferably a material sold under the trademark "Trevira" by American Hoechst Corporation, Post Office Box 5058, New York. N.Y. 10087. The material is a synthetic non-woven fabric which is a porous, flexible polypropylene material. The sheet material is capable of dissipating gas in a lateral direction so as to permit gas which gathers adjacent the sheet material to pass laterally outwardly through the sheet material. PA0 (b) Applying approximately one-fourth inch of bentonite over the top of the base material. PA0 (c) Applying plain kraft paper or other biodegradable material over, the top of the bentonite. This material must be capable of degrading after hydration. PA0 (d) Stitching the sheet material to the base material with the bentonite being positioned between the two sheets of material. In the preferred form of the invention, the stitches extend in crossing diagonal lines with respect to the longitudinal axis of the sheet material so as to form diamond shaped quilted compartments between the upper sheet material and the base sheet material. The quilted compartments contain bentonite therein. The quilted arrangement prevents the bentonite from shifting during the rolling of the quilted material and during transportation. In another form of the invention, the kraft paper is corrugated so as to form elongated corrugated compartments for containing the bentonite material.
The above process was cumbersome, expensive and timeconsuming. The use of adhesive and the baking process contributed substantially to these disadvantages.
Therefore, a primary object of the present invention is the provision of an improved device for providing moisture impervient barriers and the method for using the same.
A further object of the. present invention is the provision of a new moisture impervient material which does not require baking or adhesive as in prior art devices.
A further object of the present invention is the provision of a new moisture impervient material which is easily manufactured and mass produced.
A further object of the present invention is the provision of a moisture impervient material which prevents the seepage of water and the leaching of contaminants from ponds, reservoirs. dams, municipal and industrial waste lagoons, burial sites and other applications
A further object of the present invention is the provision of a moisture impervient barrier which greatly simplifies the manufacturing process.
A further object of the present invention is the provision of a moisture impervient barrier which can be manufactured in varying thicknesses for different applications.
A further object of the present invention is the provision of a moisture impervient barrier, which is economical to manufacture, durable in use and efficient in operation.